Jordan Goodman is an Honorary Research Fellow at the Wellcome Trust Centre for the History of Medicine at UCL. His publications include The Rattlesnake: A Voyage of Discovery to the Coral Sea (2005). Paul E. Lovejoy is Distinguished Research Professor and holds the Canada Research Chair in African Diaspora History at York University. His publications include Transformations in Slavery: A History of Slavery in Africa (2nd edition, 2000). Andrew Sherratt was Professor of Archaeology at the University of Sheffield. His most recent book was Economy and society in prehistoric Europe: changing perspectives (1997).